100.000.000419170%$3
Mohammad Khojah
Under the direction of Dr. Atif Shamim
Saudi Research Science Institute
July 24, 2012
An Inkjet Printed Antenna on Leather for Mine Detection in
Battlefields
2
Overview
Overview
Introduction
• Mines
• Problem
• Objective
• Detection
• Inkjet printing
Design process
•Specifications
•Leather
•Simulating
•Printing
•Testing
Conclusion
•Results
•Conclusion
•Future work
•Improvements
•Applications
9/20/2015 3
Introduction
Problem
9/20/2015 4
Bulky
Expensive
Not user friendly
Source Nation/ Defence Days, Esplanade des Invalides, Paris, France, September 24-25, 2005
Mine Detector
9/20/2015 5Introduction
Objective
Fabricate an inkjet printed antenna
for mine detection
that will be embedded in a shoe.
9/20/2015 5
Introduction
Mine Detection
The Project Common Mine Detectors
Antennas Coils
Electromagnetic waves Magnetic fields
Reflection Change in magnetic field
9/20/2015 6
Introduction
Novel Aspects
• Novel printing surface
• Hot air station sintering
• Inkjet mine detector
9/20/2015 7
Introduction
Challenges
The mine detector has to be:
• Cheap
• Flexible
• Small
• Efficient
• Reliable
9/20/2015 8
Introduction
Inkjet Printing
9/20/2015 9
Design Process
Design Process and Evaluation
Antenna Specifications
Comparing Leather
Simulating the Antenna
Printing the Antenna
9/20/2015 10
Design Process
Antenna Specification
Frequency 2.4 GHZ
Wavelength 12.5 cm
Gain 2 dB
Impedance 70+j30
Type Dipole
Range > 5 m
9/20/2015 11
Design Process
Comparing the Leather
Type of Leather Thickness Permittivity Loss Tangent
Black Leather I (Car Seat) 0.5 mm 1.8 C/m2 0.01 δ
Black Leather II ( Clothing) 0.5 mm 2 C/m2 0.01 δ
Brown Leather I (Car Seat) 1.0 mm 1.2 C/m2 0.018 δ
Brown Leather II (Car Seat) 0.56 mm 1.8 C/m2 0.027 δ
9/20/2015 12
Design Process
Antenna Design
9/20/2015 13
Design Process
Gain of the Simulated Antenna
9/20/2015 14
𝑃𝑟
𝑃𝑡= 𝜎
𝐺2
4𝜋
𝜆
4𝜋𝑅2
2
R = 5.98 m
9/20/2015 15Design Process
Range of the Simulated Antenna
9/20/2015 15
Design Process
Impedance of the Simulated Antenna
9/20/2015 16
Reactance = 42
Frqfreq, GHZ
Imp
ed
ance
Ω
Resistance = 67
Determining the Layer Count
• 1 cm x 1 mm
• Four nozzles
• Sintering at 350°C
Design Process9/20/2015 17
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 5 10 15 20 25
Layers
Res
ista
nce
ΩΩ
Design Process
Printing
First Antenna Second Antenna
10 layers 10 layers
Oven sintering Hot air station
160°C 350°C
3 hours 3 minutes
9/20/2015 18
Antenna Testing
• Measuring resistance
• Measuring impedance
• Measuring return loss
9/20/2015 19Results9/20/2015 19
Heigh
t o 1
.22
1
Width of 1,628 mm
Results
Impedance
9/20/2015 20
Results
Return Loss
9/20/2015 21
retu
rn lo
ss, d
Bm
freq, GHZ
Efficiency Determination
−25 𝑑𝑏𝑚 = 𝑙𝑜𝑔20𝑉𝑟𝑒𝑓
𝑉𝑖𝑛𝑐
𝑉𝑟𝑒𝑓
𝑉𝑖𝑛𝑐= 0.56 = 5.6%
• 94.4% of the signal power will enter the antenna
• Due to the resistance of the ink, some of the signal power will be dissipated.
9/20/2015 22Results9/20/2015 22
Conclusions
• The printing process is inconsistent
• Leather is a decent substrate
• Our antenna closely meets the specifications
• Matching impedance was achieved
9/20/2015 23Conclusions 9/20/2015 23
Conclusions
Possible Applications
• Shoes that guide blind people
• Part of a radar system
• Electronics printed on clothes
• Treasure hunting
• Any situation where a device needs to sense nearby objects
9/20/2015 24
Parameters to Explore
• Printer
• Ink
• Substrate
• Sintering
9/20/2015 25Conclusions9/20/2015 25
Next Steps
• Choosing a transceiver
• Connecting the antenna
to the transceiver
• Testing the system
• Building the final prototype
9/20/2015 26Conclusions 9/20/2015 26
Acknowledgments
9/20/2015 27Acknowledgments 9/20/2015 27
• Dr. Atif Shamim
• Fahad Farooqui
• Dr. John Dell
• Tutors
• Benjamin Lei
• SRSI
• CEE
• KAUST
• SRSI students
• My family
Q/A